Journal of Synchrotron Radiation

Volume 15, Part 3 (May 2008)

diffraction structural biology

J. Synchrotron Rad. (2008). 15, 258-261 [ doi:10.1107/S0909049507066769 ]

Performance of an electron gun for a high-brightness X-ray generator

T. Sugimura, S. Ohsawa and M. Ikeda

Abstract: A prototype thermionic electron gun for a high-brightness X-ray generator has been developed. Its extraction voltage and design current are 60 kV and 100 mA (DC), respectively. The X-ray generator aims towards a maximum brilliance of 60 kW mm^-2. The beam sizes at the rotating anticathode must therefore be within 1.0 mm × 0.1 mm and a small beam emittance is required. The fabricated electron gun optimizes an aperture grid and a Whenelt electrode. The performance of the prototype electron gun measured using pulsed-beam tests is as follows: maximum beam current, 85.7 mA; beam focus size at the rotating anticathode, 0.79 mm × 0.13 mm. In DC beam tests, FWHM beam sizes were measured to be 0.65 mm × 0.08 mm at the rotating anticathode with a beam current of 45 mA. The beam current recently reached 60 mA with some thermal problems.

Keywords: electron gun; DC beam; X-ray generator.